


The Unforgotten Promise

by hummerhouse



Category: Teenage Mutant Ninja Turtles (TV 2003)
Genre: F/M, Prize Fic, Romance, Surprises, request
Language: English
Status: Completed
Published: 2017-03-15
Updated: 2017-03-15
Packaged: 2018-10-05 14:21:03
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,173
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/10310174
Author URL: https://archiveofourown.org/users/hummerhouse/pseuds/hummerhouse
Summary: Disclaimer: The TMNT are not mine. No money being made.Word Count: 4,181 one shot 2k3Rated: PG-13Summary:  Ten years have passed since Donatello and his brothers saved a young girl and her family from bank robbers.  Many things have happened in the intervening time and that rescue is long gone from Don's memory.  But for young Katie, it's something she's never forgotten.!!~~Winnerin the TMNT Universal Reader’s Choice Awards 2017: (General) Most Interesting Original Character (Katie) 2nd Place~~!!





	

**Author's Note:**

  * For [Sherenelle](https://archiveofourown.org/users/Sherenelle/gifts).



> A prize fic for the incredible Sherenelle for her 1st place win in the Artist Nexus Year End Challenge. Sherenelle asked for a story based on the picture she drew of a grown up Katie meeting Don again. That picture is featured here as the preview art for this story. Katie is the young girl OC in this story "Donatello's Duffel" found here <http://archiveofourown.org/works/2051169>  
> 

            Ten years was a long time for anyone, but especially so for a mutant turtle.  Survival meant staying hidden and that in turn meant a lot of hard work.

            This was particularly true for Donatello.  His small family had been forced to move to three different homes due to the destruction of each of the previous ones.  Every time they moved, Don had to provide power, light, water, and security systems.

            Those were just the necessities.  After that was done, or sometimes while he was still trying to accomplish the major things, he also worked on supplying the niceties such as an entertainment system and working appliances.

            All of this while also practicing his ninjitsu skills on a daily basis and performing his share of the chores.  To say that Donatello’s days were full was an understatement.  His nights were just as busy because he and his brothers patrolled their city, looking to prevent crime or to set things right once something had already happened.

            Donatello got by on much less sleep than his siblings and he was used to it, though sometimes exhaustion took its toll.  When his brothers noticed, they’d do everything they could to get him to rest.  The problem was that Don could be very stubborn.  If there was a task he felt he needed to finish, he wouldn’t go to bed until it was done.

            Even after they’d gotten settled into a new home the list of things requiring Don’s attention was long.  Everything they owned was secondhand and most of the time had been thrown out by some human who’d gotten every bit of use they could out of it.  Getting something working was only part of the battle, the rest was in keeping it working.

            Because of this, Don often needed supplies, and that meant trips to the world above ground were necessary.  If his brothers were sleeping, Don would make those excursions by himself.

            During one such expedition Donatello experienced a very strong sensation that he was being watched.  He was at his favorite junk yard, looking for a specific part that would get all four burners on their stovetop operating again.  As he struggled to pry that part loose from an old stove, he was hit by the feeling that eyes were on him.

            Being a trained ninja and someone who had been raised with a constant fear of danger, Donatello did not shrug off that perception.  Don’s friend the Professor had not mentioned seeing anyone who was out of place lingering around the junk yard, but if it were Bishop’s men or the Foot, they’d likely make sure that they weren’t spotted by the yard’s regular inhabitants.

            Suddenly on high alert, Don relinquished the part he’d come for and swiftly slid into the shadows.  As quickly as he could, he changed positions, fading in and out of the piles of junk like a wraith.  He was not quite as smooth as his brother Leonardo was at the Way of Invisibility, but then Leo wasn’t the one who lugged around a forty pound duffel bag.

            Whoever had been watching him was far less skilled.  Almost as soon as Don had started moving, he heard the sound of shoes on gravel and clothes brushing against metal.  This was not a threat from Bishop or the Foot, but it could be a Purple Dragon crony.  They must have somehow avoided the homeless denizens by taking up a perch long before sundown.

            If it were Raphael who had been discovered, the family hot head would have circled around and jumped the person following him.  This was not Donatello’s way.  He preferred avoiding the conflict in the hopes that he could someday make use of his favorite junk yard again.

            Though curious about who had lain in wait for him, Don did not linger.  Circling around to where he’d parked Raph’s motorcycle, Don quickly started it up and sped out of the junk yard. 

           Half a block past the gates he saw a small car parked at the curb, one that had not been there when he’d arrived. Since it was squeezed in between two other vehicles, Don could not see the license plate number and didn’t want to take a chance on stopping.  Instead he made a mental note of the make and model and then quickly returned home.

           The following morning as Don sat at the table sipping his coffee, Michelangelo entered the kitchen, yawned widely, and gave his genius brother a look of reproach.

           “Did you even go to bed last night?” Mikey asked.

           “Yes,” Don said shortly, staring at the table top as he waited for the caffeine to kick in.

           “Let me rephrase that,” Mikey said, chuckling as he grabbed a clean pan and set it on the stove. “Did you get any _sleep_ last night?”

           Don’s sigh turned into a yawn. “A couple of hours.  I’ll probably trip over my own bō staff during practice.”

           “Your own fault,” Mikey said without the least bit of sympathy. Frowning, he began turning knobs until he got one of the burners to light.  “I thought you were going to fix the stove.”

           “I was,” Don said, watching his brother grab eggs from the refrigerator. “I need parts in order to do that and my trip to the junk yard last night was cut short.”

           “Why? What happened?” Mikey asked, whipping eggs into a bowl.

           “Someone else was there,” Don said. “I think they were tracking me.  Since I didn’t feel like getting into a fight, I left without seeing who it was.”

           “You don’t know who it was? Were they alone?  Couldn’t have been the Foot or the Purple Dragons,” Mikey said.  “They would have attacked before you got a chance to leave.”

           “The Professor hasn’t seen any of them hanging around the junk yard,” Don said. “I checked with him before I started shopping.  Pretty sure it wasn’t Bishop’s men either.  As I was leaving I saw a small car at the curb that wasn’t there when I first arrived.  It wasn’t the type of vehicle any of our usual enemies would be driving.”

           “Curious citizen? Junk yard employee?  Reporter looking for a story?” Mikey posited.

           Don took a sip of coffee and grinned. “If you’re supplying me with examples of how wild your imagination can be, that’s something I already know.”

           Mikey set a plate of scrambled eggs in front of his brother and sat down opposite him with a plate of his own. “So what are you going to do?”

           “Guess I’ll hit a different junk yard,” Don said with a sigh. “It’s not like I can go to an appliance store for parts.”

           “Lots of stuff we can’t do,” Mikey said around a mouthful of eggs. “We manage.”

XXXXXXXXXXXXXXXXXX

            There weren’t many things that Katie remembered from when she was very young.  Old memories got tucked into the recesses of the brain to make way for new ones.  One thing she did recall vividly was how her family had been rescued by what she at the time took to be odd looking men in green outfits.

            Bank robbers had taken the entire family hostage in order to get her father, a bank manager, to open the bank for them.  The green men had come out of nowhere and within a matter of seconds, had taken down all of the men involved in the attempted heist.

            Only now Katie believed that the green wasn’t actually an outfit or disguise, it had been their real skin color.  They were turtles, real live, walking, talking turtles.  That Don, the champion she still dreamt about, was a turtle.

            Katie felt no dismay at the idea that her hero wasn’t human.  For ten years she had thought about him, about how he had faced down gun carrying thugs, about how he’d effortlessly overturned a couch to protect Katie and her siblings, and about how gentle his voice sounded when she’d talked to him.

            She also thought often about the promise she’d made.  Katie had told Don that when she grew up, she was going to marry him.  She’d sealed that promise with a kiss on his cheek.

            As she got older Katie knew that wasn’t a realistic pledge, but that didn’t dampen how she felt about her rescuer.  Always a curious person, Katie began to dig into the events of the night when the turtles had come and gone from her life.

            She learned how the lights had been disabled, about how the cameras had been jammed, and during the trial, how someone had picked the lock on the van where her mother was held in order to save her.

            Remembering the duffel bag that Don had carried, Katie was fairly certain that he was responsible for all of those things.  That meant that he was probably smart, maybe even very smart.

            Even though she was only eight at the time of the spoiled bank robbery, Katie had decided to become as smart as she could in order to be Don’s equal.  When she met him again, she didn’t want to sound unintelligent.

            And meet him she was determined to do.  Katie began to study hard, to take every advanced placement course that was offered, and to excel in every subject.  She would have graduated valedictorian of her high school if she hadn’t tested out in her sophomore year and gone on to college.

            Possibly due to her experiences during that fateful night ten years earlier, Katie found that her interests were drawn to the legal system.  She began to study the law and she decided to become a lawyer.

            As with anything she tackled, Katie became very adept in her field of study.  She was at the top of her class and clerking part time at a very prestigious New York City law firm.

            One of the things at which Katie excelled was research.  That skill came in handy as an aid in her search for Don.  She spent most of her free time scouring old newspapers looking for reports of strange sightings and then perused those to see if they fit the turtle’s modus operandi.

            Katie’s small efficiency apartment was stuffed full of boxes containing her research.  One entire wall was covered in graphs and charts she’d created, with pictures and maps she used in trying to pinpoint their location.

            It hadn’t taken long for her to figure out that they lived under the city.  Exactly where was another matter entirely.  The sewer system was vast, not to mention the many maintenance tunnels, old unused subway tunnels, subbasements in abandoned buildings, and tunnels containing city utilities.

            Finding their home would be next to impossible.  Katie did not allow that to discourage her because she knew, from personal experience, that they moved about above ground and could be tracked that way.

            There was a pattern in the turtle sightings.  It took her a while to distinguish it, but when she did, Katie was elated.  It showed her that the mutants were seen most often in certain locations, one of which was the junk yard she had gone to the night before.

            Her hunch that watching the junk yard would prove fruitful had played out almost perfectly.  She had gotten a glimpse of Don himself.  True, it was only a flash of purple because she’d underestimated how quickly he could move, or that he might sense her presence, but she knew it was him.

            He’d gotten away but that didn’t dampen the elation Katie had felt at learning with absolute certainty that he too had kept his promise never to leave New York.

           Because she knew that Don was cautious, Katie was certain that the junk yard was now a bust. He wouldn’t return there for a very long time.  Fortunately, that wasn’t the only location she’d pinpointed in her research.  There were other places where she could meet up with her turtle again.  It just required patience and Katie had a lot of that.

XXXXXXXXXXXXXXXXXX

            The first thing Donatello saw was her purple scarf.

            He was returning home from spending an afternoon at April O’Neil’s apartment.  In exchange for the parts he needed for the stove, which April had ordered online, Don had repaired several items that April hoped to sell in her shop.

            Since it was daylight out when he’d left the lair, Don had come by way of the entrance into April’s basement and was now going home by the same route.  He’d made it down to her basement and halfway to the hole he’d blown in her wall years earlier when a young woman stepped through that opening.

            Stopping in shocked surprise, Don waited as the woman approached him.  She had long blonde hair, a slim lithe figure, and wide blue eyes.  Something about those eyes struck a chord of memory, but he couldn’t quite grasp it.

            Though it was apparent that she’d come through the tunnels just to find him, the woman seemed a bit timid, grasping her arm self-consciously as she looked into his face.  Don decided to wait for her to make the first move.

            In a soft voice she said, “Hey, Don.”

            It was her voice that finally put it together for Donatello.  A flashback from his past caught up to Don in that moment and he knew who she was.

            “Katie?” Don asked as verification.

            Her smile was filled with genuine delight.  “You remember me!  I was afraid that after all these years you wouldn’t.”

            “What are you doing here?  How did you even find this place?” Don asked, puzzled.  If Leo was here they would already be going into defensive mode, preparing for the worst case scenario, but Don felt no threat of any kind from the young woman.

            “I’ve been looking for you for years,” Katie answered.  “I studied patterns in order to find you and I’ve been watching the places I discerned were ones you went to the most often.”

            Realization struck Don then.  “That was you in the junk yard the other night,” he said.

            “I should have called out to you,” Katie replied as an acknowledgement.  “In my excitement to surprise you I forgot that you probably wouldn’t react well to being followed.”

            “I’m a mutant, Katie.  I have to remain unseen,” Don told her.

            “I know,” Katie said, her cheeks pinking up in a becoming manner.  “I’m sorry if I gave you a scare.  Finding you has become something of a life’s mission for me.  When I lost you at the junk yard, I decided to keep an eye on Miss O’Neil’s apartment in the hopes you’d come here.  I saw you through her window.”

            “I’ll have to remember to close the blinds when I’m here,” Don said almost to himself.  Brow furrowing, he asked, “But why have you been searching for me?  We met for only a few minutes over ten years ago.”

            If possible, Katie’s cheeks turned an even deeper shade of pink.  “I know this is going to sound like the imaginings of a pubescent child, but I’ve often thought about what I told you the night you rescued my family.  The more I remembered about that night and about you, the more I understood how right it felt for me to pursue that dream.”

            “What you told me?” Don asked, trying to recall what she’d said to him.  It had been a very short conversation and he’d been a bit nonplussed at having a young girl fling herself at him.  He did recall that her thanks had made his night.

            “I promised to marry you when I grew up,” Katie said, her blue eyes sparking a challenge.

            Don didn’t quite know what to say to that.  Of course he hadn’t taken her seriously at the time, she’d been a child.  But here she was now, apparently fulfilling a quest to find him so that she could remind him of that girlish vow.

            “You do know that isn’t possible, right?” Don asked gently.

            Her laugh had a pleasant melody to it.  Katie had grown to be an attractive young woman, something that did not go unnoticed by Don.  But her comeliness did not change the fact that there was a great many differences between them.  He had to know exactly what she expected would come of their meeting again.

            “My whole life I’ve been told that certain things weren’t possible,” Katie said, her tone serious even though a small smile lingered on her lips.  “I decided that the only impossible things were the things you didn’t try for.  My attitude has a lot to do with meeting you and your brothers.  I started college at fifteen, Don.  I needed to show you that I work hard for the things that I want.”

            “I’m proud of you for that, Katie, I am.  But you should be working hard because you want to better yourself, not as a way to impress me or anyone else,” Don said.  He was touched by her revelation that he’d been such a strong influence, but he feared that she’d let her fantasies hold too much sway over her life decisions.

            “Your existence is dangerous,” Katie said in response.  “You’ll probably never be able to make your presence known to more than a very select few people.  Survival is hard work and you have to scavenge for things that humans take for granted.  You four are the only ones of your kind.  Have I hit the main points?”

            “For the most part,” Don acknowledged.  “You’ve forgotten a couple.  My prospects are few, my family comes first, and our enemies have no qualms about using the people we know to get to us.  I would never ask someone to risk that.”

            “Free will is a beautiful thing,” Katie said, her expression kindly but her tone unyielding.  “It means that I get to choose how much risk I can face.  I’ve never been one to take the easy route to anything, Don.  Knowing you for even a few minutes has been one of the most positive things I’ve ever experienced.  All I’ve ever wanted from that time on was to have you in my life somehow.”

            Don was in something of a quandary.  While he didn’t want to place her in peril by association, Katie seemed too tenacious to accept any attempt he might make to dissuade her.  Given that she’d worked to learn which junk yard he frequented and about April being close to his family, Don didn’t think Katie would stop until she discovered where they lived.

            “I’m not a stalker,” Katie said, as though reading Don’s thoughts.  “I learned from my father to be very forthright about what I want, to attempt to make those dreams come true, and to relinquish those things that are out of my reach.  I needed to find you again to prove to myself that you weren’t a figment of a child’s imagination.  There have been many times that I’ve had romantic fantasies about you, but if you don’t find me appealing . . . . “

            “It isn’t that,” Don said quickly.  “You grew to be a very attractive woman.  But there aren’t just lifestyle compatibility issues, there’s also our age difference, the fact that I age differently, and that I’m a _turtle_.  Don’t you want a human guy?  Someone who can offer you a real future and children of your own?”

            Katie was shaking her head even before Don finished speaking.  “I have yet to meet a guy who is as good looking to me as you are.  Sorry, I guess I’m a one turtle girl.”

            “It’s probably just a crush Katie,” Don said wisely.  “Years have gone by and you’ve built me into something more than I am.”

            “That’s very possible,” Katie replied.  “I suppose you could let me down lightly and send me on my way, but then I’ll just keep believing that my Prince Charming has gotten away from me.  I’ll compare every guy I meet to my larger than life image of you, and will find them all wanting.”

            Don did not miss the mischievous gleam in her eyes or that hint of a smile that once more lifted the corners of her mouth.  Despite himself, he found that he was more and more intrigued by Katie.

            “Now you’re just teasing me,” Don said good-humoredly.

            “Of course I am,” Katie said.  “I’m standing here in a stranger’s basement because I wanted you in my life again and you really think a few obstacles will dissuade me?”

            “And if things don’t work out the way you’d like?” Don asked.  “What happens then?”

            “If the question is will having known me bring another negative to your existence, the answer is no,” Katie said.  “I’m studying law.  I believe in justice.  I don’t approve of retribution as a solution for hurt feelings.  All I want is a chance to be a friend, as good a one as Miss O’Neil appears to be.”

            “April O’Neil has paid the price several times over due to our friendship,” Don told her.

            “Yet she’s still here, risking everything to continue being your friend,” Katie said.  “As soon as I learned that she was close to you guys, I researched her.  I know she used to work for Baxter Stockman and that her home and shop were once burned to the ground by a gang with whom you are enemies.  She’s the type of strong, brave, intelligent woman that I want to emulate.  I can also be wily and skillfully circumspect.  After all, I’ve been on _your_ trail for years and you never knew I was there.”

            “Touché,” Don said, chuckling.  “If you hadn’t told me you were studying law, I might have deduced that for myself.  You’ve certainly made some very cogent arguments.”

            “Enough to have won my case?” Katie asked playfully.  “Can we be friends?”

            Don grinned, enjoying both her enthusiasm and her wit.  “I concede this round is yours.  My brothers and I would be honored to count you as a friend.”

            He held his hand out to her and Katie took it, her grip firm.  Then before Don could react, Katie darted forward to kiss his cheek, her mouth lingering near his as she faced him again.

            “Friendship will do for now,” Katie murmured, “at least until I can persuade you that I could be more.”

            Stepping back, she winked at Don, her smile impish.  Though surprised by her action, Don couldn’t help but find her guile amusing and just a little stimulating.  That word actually described Katie’s personality quite well.  There was something both exciting and challenging about the unexpectedness of her character and her intellect.

            “You do know that if you hang around with us, you’ll probably have to fight with more than your debate skills,” Don said.  “That’s another fact of our lives.”

            “Damien and Walter, my brothers you’ll remember, were so enthralled by the weapons display your brothers put on for them that they insisted my father enroll them in martial arts classes.  Of course, I wasn’t going to be left out, so I took classes too.  I’m a black belt in Taekwondo and so are they.  Meeting you guys was good for all of us,” Katie said.  “There are probably a lot of people whose lives you’ve touched and changed for the better.  I’d like to make that kind of difference.”

            Don had often wondered if the people he and his brothers helped ever thought about them afterwards, and if so, were those remembrances positive?  It seemed that in at least one case the answer was a resounding yes.

            “Real fighting isn’t the same as demonstration or tournament bouts,” Don warned.  “It isn’t as pretty either.”

            “I know that, I haven’t forgotten a single move you and your brothers made the night you saved my family,” Katie said.  “That isn’t to say I couldn’t benefit from learning even more, if a certain turtle in a purple mask wanted to teach me.”

            If nothing else, Katie was persistent, reminding him a lot of two of the other strong females he knew best, April and Angel.  Smiling, Don said, “I think that can be arranged.  If you give me your phone number, I promise to call you.  For now though, let me walk you back through the tunnels.”

            As Don moved forward, Katie beamed with delight and took his hand, walking alongside him.  This was exactly how she’d hoped their reunion would go.  Maybe the future would take them down the path she’d always daydreamed about or maybe it wouldn’t, it was certainly too soon to tell.

            But for now Katie had exactly what she wanted; she had found Don again and been accepted into his world.  She would continue to work hard to show Don and his family how much she cared for the handsome, intelligent turtle and to become his close companion.

            With perseverance and some luck, Katie might also find a way to convince him that she could be more than just a friend.

The End

**Author's Note:**

> This lovely art badge was created by Felhesznelenev (DA)  
> 


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